The Roots & Elvis Costello Team Up for Album in 2013

"It was really love at first sight," Questlove says of the project, to be followed by another Roots record "& Then You Shoot Your Cousin"

Since becoming the house band on NBC's "Late Night With Jimmy Fallon" in 2009, the Roots have backed everyone from Bruce Springsteen and Paul Simon to Bon Iver and Carly Rae Jepsen. And now, another collaboration with a legendary artist that began on the "Late Night" stage is leading to a full-length album.

Roots drummer Ahmir "Questlove" Thompson has exclusively revealed to Billboard that the group is prepping a collaborative project with Elvis Costello that should be out sometime this year. "It was really love at first sight," Thompson says of Costello, who has made three "Late Night" appearances, including a performance in February 2012 during a week-long tribute to Bruce Springsteen. "The second time he came on, we surpassed the first one. So by the third time, he was like, 'Let's stop messing around and do something together.'"

The initial plan was to cut just a few tracks, but those sessions proved fruitful enough for the artists to keep going. Says Thompson, "we had 13 or 14 songs, but then we said, 'Ooh! Wait a minute! Let's replace four of these songs with four better songs! And now we have the tightest 12-14 song collection out of about 20 songs that we made."

In the near future, Costello and the Roots plan to mix and master the as-yet-untitled LP with assistance from Roots engineer Steven Mandel, who is co-producing the project with them. It is unclear at deadline which label will release the album. "We kind of have the freedom to take it around, whether it's to Elvis' people or Def Jam's people," says Thompson. "I can just say that it is brilliant."

In addition to the Costello album, the Roots are planning to release their own new LP, "& Then You Shoot Your Cousin," either in late 2013 or early 2014. "We're in the genesis of that right now," says Thompson of the follow-up to 2011's Grammy-nominated "Undun."

As reported earlier today, Thompson is also heavily involved in D'Angelo's long-awaited follow-up to 2000's "Voodoo," which he says should finally be released this year. The Roots also just announced the lineup for their sixth annual Roots Picnic, set for June 1 at Penn's Landing in Philadelphia.